Cylinder relief-valve.



No. 792.378. PATENTED JUNE 13, 1905.

M. R. ZEHNDER. CYLINDER RELIEF VALVE.

APPLICATION FILED JUNE II 1904.

4 SHEETSSHEET 1.

PATENTED JUNE 13, 1905. M. R. ZEHNDER.

CYLINDER RELIEF VALVE.

APPLICATION FILED JUNE 11, 1904.

4 SHEETS-SHEET 2.

7 PATENTED JUNE 13, 1905. M. R. ZEHNDER.

CYLINDER RELIEF-VALVE.

APPLICATION FILED JUNE 11. 1904.

4 SHEETS-SHEET 3.

ww M Q 3 Q smmuboz e/md/r lxhkmmao MGM? No. 792,378. PATENTED JUNE 18,1905.

M. R. ZBHNDBR;

CYLINDER RELIEF VALVE.

APPLICATION FILED JUNE 11, 1904.

4 SHEETS-SHEET 4.

avwewtoz UNITED STATES Patented June 13, 1905. I

PATENT ()FFICE.

MORRIS R. ZEHNDER, OF SCRANTON, PENNSYLVANIA, ASSIGNOR TO THE ZEHNDERVALVE AND BRAKE MANUFACTURING COMPANY, OF SCRANTON, PENNSYLVANIA, ACORPORATION.

CYLINDER RELIEF-VALVE.

SPECIFICATION forming part of Letters Patent No. 792,378, dated J 1111613, 1905.

Application filed June 11, 1904- Serial No. 212,164.

To all whom it may concern:

Be it known that I, MoRRIs R. ZEHNDER, a citizen of the United States,residing at Scranton, in the county of Lackawanna and State ofPennsylvania, have invented certain new and useful Improvements inCylinder Relief Devices, of which the following is a specification.

This invention comprises improvements in devices for attachment tosteam-engine cylinders adapted to relieve the cylinders ofdrainage-water, to obviate the retarding action upon the pistonordinarily caused by air compression and rarefaction within the cylinderwhen the engine is running under its own momentum, and to preventexcessive internal pressure in the cylinder; and the invention relatesparticularly to means actuated by steam or other fluid pressure forcontrolling the operation of the valves in the device at the will of theengineer to provide for certain contingencies which arise in thepractical running of locomotives.

In the accompanying drawings, which illustrate my invention, Figure 1 isa central vertical section through a steam-engine cylinder, showingdrainage and relief devices connected thereto and partly broken away andthe connections to the controlling-valve. Figs. 1 and 1 are viewsillustrating different forms of controlling-valves. Fig. 2 is a top planview, partly in section, of one of the drainage and relief devices. Fig.3 is a central vertical section through the same. Fig. 4 is an end viewof the same looking from the right in Fig. 3. Fig. 5 is a centralvertical section through a drainage and relief device in which thecontrolling-cylinder is arranged at the 0pposite end of the device fromthat to which it is attached in the previous figures, and two pistonsare arranged therein. Fig. 6 is a horizontal section through thecontrolling-cylinder of Fig. 5 on the line 6 6. Fig. 7 is a view similarto that shown in Fig. 5, only one piston being provided for operatingthe valves; and Fig. 8 is a vertical central section through one of thedrain and exhaust valves for the controlling-cylinder.

Referring to Figs. 1 to 4, inclusive, of the drawings, A indicates thesteam-cylinder of a locomotive or other steam-engine, P the piston, andB and B indicate the drainage and relief devices which are securedwithin the drainage-outlets at the ends of the cylinder. The twodrainage and relief devices are similarly constructed, and a descriptionof one will therefore apply to both. As shown in Figs. 2 and 3 of thedrawings, each device comprises a hollow casing 1, having a threadedpipe connection 2, adapted to fit into a drainage-outlet opening in thecylinder, as shown in Fig. 1, or to be connected to a pipe leading fromsuch opening. The drainage-water live and exhaust steam enter theinterior of the valve-casing 1 through the pipe connection 2, whichforms an inlet-opening 3 for the casing. An excess-pressure valve L isarranged within the casing at one side of the opening 3 and is normallyheld against its seat 5 with sufficient pressure to prevent it fromopening under the normal steam-pressure of the boiler by a spring 6, thetension of which may be varied by means of an adjustable cap or follower7, fitting around the stem 4 of the valve and having a threadedconnection 8 with the valve-casing 1. The spring 6 is interposed betweenthe end of the cap or follower 7 and the valve 4, and it will beapparent that by turning the follower the pressure of the valve againstits seat may be adjusted so that the valve will open at any desiredpressure above the normal steam-pressure in the boiler or theenginecylinder. The threaded end of the casing within which the cap orfollower 7 fits has a longitudinal slot 9 and a lug 10 at each side ofthe slot, and the follower may be clamped in any position by means of aclamping-bolt 11, extending through openings in said lugs. Anoutlet-opening 12 extends from the interior of the casing in the rear ofthe valve): through a suitable pipe connection or fitting 12*, and whenthe valve is lifted from its seat by excessive pressure in the cylinderthe steam or water, or both, as the case may be, may pass out throughthe opening 12. The excess-pressure valve& is held normally closed underall ordinary conditions and opens outwardly only under extraordinaryconditions when the internal pressure is abnormal.

A relief-valve 13 is arranged within the easing at the opposite side ofthe inlet-opening 3 and when closed is adapted to fit against avalve-seat let. The valve 13 opens inwardly and is normally held in itsopen position against suitable stops 15 in the central part of thecasing by a spring 16, which is coiled around the stem 13 of the valveand interposed between the back of the valve and an adjustable collar17, fitting around the valvestem within the casing. This collar isprovided with lugs or projections 17, which extend through slots 18 inthe wall of the easing, and the collar may be adjusted to vary thetension of the spring, as desired, by means of a nut 19, threaded ontothe exterior of the casing, as shown, and bearing against the rear edgesof the projections 17". This nut has a series of shallow notches 19 atone side arranged in diametrically opposite pairs and adapted to receivethe lugs or projections 17 upon the collar or follower 17. By turningthe nut the spring may be set so that the valve will close at anydesired fluid-pressure, which should be less than the normal livesteampressure in the engine-cylinder. The engagement of the lugs 17 with thenotches 19 prevents the accidental turning of the nut. The casing isprovided with a drainage-outlet opening 20 in the rear of the valve 13and extending through a suitable pipe connection 20. This connection, aswell as the connection 12, may be connected to a pipe 21 common to both,as indicated in Fig. 2. When applied to a locomotive, this pipeterminates at some point beneath the locomotive in preference todischarging at the side.

During ordinary movements of the engine while operating understeam-pressure the excess-pressure valve 4 remains closed, as previouslystated, while the relief-valve 13 opens automatically by the pressure ofthe spring 16 to permit the drainage-water to flow out from the exhaustend of the cylinder and is closed immediately by steam-pressure whenlive steam is applied to the end of the cylinder to which the device isconnected. As there is a relief device connected to each end of thecylinder, of course the drainage-valves in these devices will open andclose alternately, and thus drain both ends of the cylinder.

When the engine is at rest and also while running under its own momentumwith steam cut off, the drainage-valves will be held off of their seatsby the springs, and the cylinder will thus be drained at all times,whether in motion or stopped. \Vhen the engine is running under its ownmomentum, also as the drainage-valves are held open, air may enter andpass out of the cylinder by way of said valves, and the compression ofair in front of the piston and vacuum in the rear of the piston, whichnaturally result from the pumping action of the piston, are in whole orin part averted.

The back pressure in the cylinder, caused by the complete or partialclosing of the exhaustport by the engine-valve before the piston reachesthe end of the stroke, results in back pressure upon the piston, whichback pressure may be relieved through the drainagevalves if the tensionof the springs upon these valves is made suflicient to withstand suchpressure, or any desired amount of back pressure may be retained bysuitable adjustment of the springs adapting them to close at anypredetermined pressure. The valves 13,therefore, in both casings servethe several useful purposes of draining the cylinder, relieving theair-pressure within the cylinder, preventing the formation of a vacuum,and preventing or regulating the back pressure upon the piston.

It is sometimes desirable to hold the drainage and compressionregulating valves 13 against their seats and .prevent their operationas,for instance, when a locomotive is passing a station and it is desiredto prevent the escape of exhaust steam and water until the engine haspassed the station. It is also desirable at times to hold thedrainage-valves open and inoperative as, for instance, when thelocomotive has stopped for some time and the cylinders have becomecooled so that there is considerable condensation of steam when thesteam is first applied to the cylinders in starting. In such case it isdesirable to prevent the closure of the drainage-valves until thecylinders have become heated. It is also desirable at times to be ableto force the drainage-valves ofi of their seats against the livesteampressure in the cylinder. It frequently occurs in starting long heavytrains, particularly on up grades, that the engineer will open histhrottle-valve and admit steam to the cylinder; but owing to the factthat there is no slack between the cars the locomotive is unable tostart the train and the driving-wheels will not move. When this occurs,the engineer wishes to reverse his engine so as to provide slack at thecouplings between the cars of his train; but the steam-pressure upon thereversing-valve in the steam-chest is so great that with ordinary valvesit is difficult or impossible to move the reversing-valve until steamhas been cut off at the throttle-valve and the steam from the chest andsteam end of the cylinder has been allowed to escape through thedrain-pipes or to condense.

In order to provide for holding the drainagevalve inoperative either inits open or closed positions and for forcing the drainage-valve openagainst live-steam pressure, I provide a controlling-cylinder C, whichis conveniently supported upon the end of the casing 1, and within thiscylinder is arranged a close-fitting piston 22, having suitablepacking-rings on its periphery to render it steam-tight. The valve-stem13 projects through and fits closely within an opening 23 in the end 1of the relief-valve casing and into the controlling-cylinder, and thepart 13 of the valve-stem within the cylinder extends through an axialopening in the piston 22. The piston is movable longitudinally of thevalve-stem, and in order to prevent wear a bushing 24 is interposedbetween the piston and stem. The valve-stem has a shoulder 25 at oneside of the piston and a collar 26 at the opposite side of the piston,which is held in place by a nut 27 upon the end of the valve-stem, thisshoulder and collar, which form stops for the piston, being within thecylinder and separated from one another by a distance which during theordi' nary opening and closing operations of the valve will permit thevalve stem to slide through the bushing without disturbing the piston.The drainage-valve may therefore operate without being retarded in itsmovements by the piston, and the latter during ordinary operationsremains stationary and does not wear out the packing-rings. \V hen steamis admitted to one side or the other of the piston to move or hold thevalve, as hereinafter explained, the piston will be forced against oneof the stops 25 or 26, and the end of the bushing, fitting against thestop, will make a steam-tight joint which will prevent steam frompassing between the bushing and valve,; stem from one side of the pistonto the other in case there is leakage at this point.

The controlling-cylinder (J, as shown, consists of a cup-shaped castinghaving a recess 28 at its outer end to provide clearance-space for thenut and the end of the valve-stem, and this casting is secured by bolts29 to a head 30, which is threaded, as shown, or otherwise suitablysecured to the end of the relief-valve casing, this head forming one endof the cylinder. By removing the bolts 29 the cylinder may be removedfor the purpose of repacking the piston or inserting a new bushing.

Inlet-openings 31 and 32 for steam or other fluid under pressure arearranged at the outer and inner ends of the cylinder, respectively, and,as shown in Fig. 1, the openings 31 in the cylinders of both drainagedevices B and B are connected by a pipe 31 to a valve D, which isarranged within the engine-cab at a point convenient to the engineer.Similarly, the openings 32 are connected by a pipe 32 to the valve D.The valve D (shown in Fig. 1) is so arranged that live steam or otherfluid under pressure may be admitted from a pipe S, connected with thesource of supply through the passage-ways e and e to either of the pipes31 or 32, respectively, and exhausted through the port 6 or the fluidmay be shut off from said pipes. W'hen fluid is admitted to the pipe 31,as shown in Fig. 1 of the drawings, the controlling-pistons 22 will, asshown in Fig. 2, be forced against the shoulders 25 of the relief valvestems, and this fluid-pressure, together with the pressure of thesprings 16, will hold the relief-valves 13 open against fullboiler-pressure applied to the inner side of said valves. If thelocomotive in attempting to start a heavy train, for instance, becomesstalled with live steam applied to the right-hand end of one of theengine-cylinders, as shown in Fig. 1, and the reversing-valve E is heldagainst its seat by live-steam pressure, and therefore diflicult tomove, the admission of steam or other fluid under pressure by thehand-valve D, through the pipe 31, will force open the relief-valves, asshown in Fig. 1, and the live steam may pass out through the drainageand relief device B, thus relieving the pressure upon thereversing-valve E in the steam-chest, so that the latter may be readilymoved into position to reverse the locomotive and provide sufficientslack in the train to enable the locomotive to start. When it is desiredto keep the drainage-valves closed against their springpressures, fluidunder pressure is admitted from the valve D, through the pipe 32, intothe inner ends of the controlling-cylinder C, and thecontrolling-pistons 22 are thereby forced outwardly against the collarsor shoulders 26, as shown in Fig. 3, and the reliefvalves will thus bedrawn to and firmly held against their seats. This is desirable, aspreviously stated, for the purpose of shutting off the exhaust whilepassing stations, and it may also be desirable to keep thedrainage-valves closed when the locomotive is running and there islittle or no drainage to be disposed of. \Vhen pressure is shut off fromboth of the pipes 31 and 32, the piston assumes an intermediateposition, and the drainage-valve stem slides freely through the bushingin the piston as the valve plays back and forth, while the pistonremains stationary.

Very small drainage-openings (Z extend through the lower wall of thecontrolling-cylinder for the purpose of permitting the water ofcondensation to pass out without causing much loss of steam, althoughsmall automatic drain-valves E, such as are shown in Figs. 7 and 8 andhereinafter referred to, may be arranged in the lower wall of thecylinder for drainage and exhaust purposes.

Instead of employing a normally closed controlling-valve for admittingand exhausting the actuating fluid to and from the controlling-cylindera valve D, (shown in Fig. 1,) may be employed, in which the valve in itscentral position normally admits the actuating fluid through thepassage-way f and both pipes 31 and 32 to opposite sides of thecontrolling-piston, and when the valve is moved in either direction fromits central position the fluid from one of the pipes will exhaustthrough the ports f or f relieving the pressure on one side of thepiston and allowing the latter to be actuated by the pressure which ismaintained at the opposite side of the piston. This is advantageous incold weather when steam may be employed as an actuating medium, and thusprevent ice from forming in the cylinder.

In Fig. 1 I have shown a controllingwalve D which is not provided withan exhaustport and which is suitable for operating thecontrolling-piston, the exhaust taking place through the smalldrainage-openings (Z in the controlling-cylinder or through theautomatic drain-valves E. In Fig. 1 the valve has a single passage-wayg, which is normally closed in the central position of the valve, butwhen turned in either direction from the center may connect with one orthe other of the pipes 31 or 32, and thus admit the actuating fluid toeither side of the controlling-piston, as desired. When the valve isagain closed, the condensation and leakage through the drainage-outlets(Z or the drain-valves E will reduce the pressure on the piston in afewmoments, so as to render the piston again inoperative.

In case of breakage of the valve-stem 13, which may sometimes occur inthe operation of the device, it is desirable to provide means forholding the valve 13 against its seat to prevent the escape of steam. Incase of wear between the valve 13 and the stops or bridgepieces 15,which would permit the valve to open farther than is suitable for themost -efficient operation of the valve, it is desirable to provideadjustable means for limiting the opening movement of the valve. Forthese purposes, as shown in Figs. 2 and 3, I extend a regulating-screw33 axially through the valve-stem 4, its inner end, as shown,extendinginto the interior of the casing between the valves 4 and 13.The screw 33, as shown in Fig. 3, has a threaded connection 34 with theouter end of the valve-stem 4, and the screw may be locked in anydesired adjustment by means of a nut 35, threaded onto the screw andadapted to abut against the outer end of the valve-stem. In case ofbreakage of the valve-stem 13 the screw 33 may be turned, so that itsinner end will bear against the valve 13 and hold the latter firmlyagainst its seat, the tension on the spring 16 being at the same timereleased, if necessary, by turning the nut 19. Should the stops orbridgepieces 15 and the parts of the valve 13 which strike the stopsbecome worn or hammered, so as to permit the valve to open farther thanis desirable, the ad justing-scre w may he turned so that its inner endwill form a stop for the valve in the correct position.

In Figs. 5 and 6 I have shown a modified form of device in which thecontrolling-piston also normally remains inactive. Instead of extendingthe drainage and compression regulating-valve stem into thecontrolling-cylinder, as in Figs. .2 and 3, a rod is extended throughthe excess-pressure valve and its stem into the controlling-cylinder,and a double piston is arranged in the latter in such manner that byadmission of steam or other fluid pressure to the cylinder this rod maybe forced against the drainage-valve to hold the latter in its closedposition when desired, or the excess-pressure valve may be held in itsopen position to relieve the cylinder when desired.

Referring to Figs. 5 and 6, 36 indicates the drainage andcompression-regulating valve, which is normally held off of its seat, asshown, by the spring 37, coiled around the valve-stem 36 and interposedbetween the valve and an adjustable cap or follower 38, which isthreaded into one end of the casing B and secured by a lock-nut 39. Thevalve-stem slides within an opening 38 in the follower 38. The valve 36normally rests against stops 40, similar to the stops or bridge-pieces15 in Figs. 2 and 3, and a drainage-opening 20, corresponding to theopening 20 in said figures, is arranged in the rear of the valve 36. Theexcess-pressure valve 41 is normally held against its seat, as shown, bya spring 42, coiled upon the valve-stem 41 and interposed between theback of the valve and a follower 43, whichis adjustable by means of anut 44. The follower 43 and nut 44 are substantially the same as thefollower 17 and nut 19 in Figs. 2 and 3, and the lugs 43*upon thefollower slide in slots 45, which are arranged diametrically opposite inthe casing, as shown. The valvestem 41 is tubular and projects throughan opening 46 in the end 1 of the valve-casing and into thecontrolling-cylinder C. A rod 47 extends through the tubular valve-stem,as shown, and is movable longitudinally therein. One end of this rod hasa head 47 a in front of the valve, and a piston 48 is suitably securedupon the opposite end of the rod within the controlling-cylinder. Thispiston, as shown in the drawings, is threaded onto the end of the rodand secured by a lock-nut 49, and a spring 50 is interposed between thispiston and the adjacent end of the valve-stem 41, so that the head 47 isnormally drawn against the valve 41. Another piston 51 is arrangedwithin the cylinder and secured, as shown, upon the end of the tubularvalve-stem. Ports 31 and 32 corresponding to the ports 31 and 32 ofFigs. 2 and 3, are arranged in the side of the cylinder for theadmission of fluid under pressure from a controlling-valve in theengine-cab.

In operation when steam is applied during ordinary movements of theengine the valve 36 opens and closes automatically and the valve 41remains closed. If it is desired to hold the valve 36 against its seatfor any purpose, fluidpressure is admitted through the port 31, and thepiston 48 is thereby moved to the right, compressing the spring 50 andforcing the rod 47 against the valve 36, which is thereby moved and heldagainst its seat. When the pressure is released from the left-hand endof the cylinder, the rod 47 is returned by the spring 50, and the valve36 is forced open by its spring 37. When it is desired to maintaincommunication between the engine-cylinder and the atmosphere while theengine is in motion under steam-pressure for drainage or other purposes,fluid pressure is admitted through the controlling-valve and port 32 tothe right-hand end of the controlling-cylinder, and the piston 51 isthereby moved to the left, carrying with it the excess-pressure valve41, which is thereby held off of its seat until the fluid-pressure iscut off from the righthand end of the controlling-cylinder. IVhen thisis done, the spring 42 returns the excess pressure valve to its seat.

Small drainage-openings 52 or automatic valves E, Fig. 8, are arrangedat the ends of the controlling-cylinder to permit the water ofcondensation to escape, and asmall vent 53 is arranged in the wall ofthe cylinder between the pistons for the same purpose and also toprevent air compression between the pistons.

The drainage and relief device shown in Fig. 7 is the sameinconstruction as that shown in Figs. 5 and 6, and thecontrolling-cylinder is substantially the same. The tubular valvestem41", however, is shorter and is not provided with a piston, as in saidfigures. Acontrolling-piston 54 is secured upon the rod L7, and a smallspring 50 is interposed between said piston and the adjacent end of thevalvestem 41". The piston normally rests in central position in thecylinder, and the head 47 of the rod 47 is normally drawn against thevalve 41 by the spring 50.

When the actuating-fluid is admitted to the right of the piston in Fig.7, the valve 41 will be pulled to the left off of its seat, and whenadmitted to the left of the piston the rod 4E7 will be forced againstthe drainage and compression-regulating valve 36, thus closing thelatter.

In Fig. 7 I have shown automatic drain and exhaust valves E applied tothe controllingcylinder at its ends. These may be of any suitable formadapted to close when full pressure is admitted to thecontrolling-cylinder and to open when the pressure falls below apredetermined amount. Each drain and exhaust valve, as shown in detailin Fig. 8, comprises a tubular casing having a threaded nipple 55,adapted to fit into a drain-port of the cylinder, an annular shoulder56, which abuts against the outer wall of the cylinder, avalveseat 57within the casing, lateral openings 58 below the valve-seat, and athreaded opening in its lower end, into which is fitted anadjusting-screw or follower 59. Within the casing is arranged a valve60, adapted to fit against the seat 57, but normally held off of itsseat by a spring 61, coiled around the valve-stem 62 and interposedbetween the Valve and the follower. The valve-stem, as shown,

extends through an axial opening in the follower, which forms a guidefor the valvestem. An adjustable stop 63, threaded upon the end of thevalve-stem, limits the upward movement of the valve and regulates thetension of the spring.

The area of the valve 60 is purposely made small, and the tension of thespring is adjusted so that the valve will open whenever thefluid-pressure in the controlling-cylinder is materially reduced belowthe normal pressure employed for operating the controlling-piston. Ifthe full fluid-pressure for operating the piston be admitted to one endof the controlling-cylinder through a valve, such as the valve D (shownin Fig. 1 the valve 60 at that end of the cylinder will immediatelyclose and prevent the escape of steam. When the valve D is closed, thepressure in the controlling-cylinder rapidly decreases by inevitableleakage and by condensation when steam is the fluid employed, and thepressure falls in a few moments to a point where the pressure of thespring 61 overbalances the fluid-pressure upon the valve 60 and thelatter opens, thus relieving the pressure in the cylinder and alsopermitting the latter to drain freely through the openings 58. Theexhaust from the controlling-cylinder is thus not carried back to thecontrolling-valve, but is permitted to es cape directly from thecylinder to the atmosphere. These drain and exhaust valves may beemployed on any of the cylinders shown in the drawings and with any formof controllingvalve to prevent the escape of steam and permit thecylinder to drain; but they are particularly desirable in connectionwith the simple form of controlling-valve illustrated in Fig. 1", having'ho exhaust-port, wherein they answer a threefold purpose.

I have shown in the drawings two different arrangements of thecontrolling-cylinder with respect to the valve-casing and valves; but Ido not wish to confine myself to any particular arrangement of thecontrolling cylinder and piston with relation to the valve-casing andvalves, as the controlling-cylinder may be supported and arranged invarious ways upon the valve-casing or independently thereof,

suitable mechanical connections being arranged between thecontrolling-piston and the valve which it is to operate. Where thecontrolling-cylinders are secured to the valvecasings the pipes leadingfrom the controlling-valve will not, of course, in practice extend belowthe casings, as shown diagrammatically in the drawings for convenienceof illustration.

It will be noted that in the various forms of devices illustrated in thedrawings the free normal operation of the drainage andcompression-regulating valve is not retarded or interfered with by thecontrolling-piston, which normally remains stationary, and that thisvalve may be held firmly to its seat by the piston or one of the valveswithin the casing may be held open as long as desired by the operationof the piston.

Having described my invention, what I claim, and desire to secure byLetters Patent,

the engine-cylinder, a controlling-piston arranged to hold said valveinoperative in its closed position, said piston and valve being movablerelatively to one another, and means comprising a controlling-valve, formoving said piston by fluid-pressure.

3. In a drainage and relief device for enginecylinders, a casing, anormally open valve therein adapted to close by fluid-pressure from theengine-cylinder, a controlling-piston arranged to hold said valveinoperative in its open position, said piston and valve being movablerelatively to one another, and means comprising a controlling-valve, formoving said piston by fluid-pressurep 4. In a drainage and relief devicefor enginecylinders, a casing, a normally open valve therein adapted toclose by fluid-pressure from the engine-cylinder, a controlling-pistonarranged to hold said valve inoperative in either its open or closedpositions, and means comprising a controlling-valve, for moving saidpiston by fluid-pressure in two directions.

5. In a drainage and relief device for enginecylinders, a casing, anormally open valve therein adapted to close by fluid-pressu re from theengine-cylinder, a controlling-piston arranged to hold. said valveinoperativein either its open or closed positions, said piston and valvebeing movable relatively to one another, and means comprising acontrolling valve, for moving said piston by fluid-pressure in twodirections.

6. In a drainage and relief device for enginecylinders, a casing, anormally open valve therein adapted to close by fluid-pressure from theengine-cylinder, a controlling-cylinder, a piston within said cylinderand connections between Said valve and piston whereby said valve may beheld inoperative by the piston, and means comprising a controlling-valveand suitable pipe connections, for admitting fluidpressure to saidcontrolling-cylinder.

7. In a drainage and relief device for enginecylinders, a casing, 'anormally open valve therein adapted to close by fl uid-pressure'from theengine-cylinder, a controlling-cylinder, a piston within saidcontrolling-cylinder, connections between said valve and piston,whereby, when fluid-pressure is admitted to said controlling-cylinder,the piston will hold the valve inoperative, said piston and valve beingrelatively movable, and means for admitting fluid-pressure to thecontrolling-cylinder.

8. In a drainage and relief device for enginecylinders, a casing, anormally open valve therein adapted to close by fluid-pressure from theengine-cylinder, a controlling-cylinder connected to said casing, a stemupon said valve projecting through said casing and into saidcontrolling-cylinder, a piston within the controlling-cylinder andadapted to move said valve-stem, and means for admitting fluidpressureto the controllingcylinder.

9. In a drainage and relief device for enginecylinders, a casing, anormally open valve therein adapted to close by fluid-pressure from theengine-cylinder, a controlling cylinder trolling-cylinder.

10. In a drainage and relief device for engine cylinders, a casing, anormally open valve therein adapted to close by fluid-pres sure from theengine-cylinder, a controllingcylinder connected to said casing, a stemupon said valve projecting through said casing and into saidcontrolling-cylinder, a piston Within the controlling -'cylinder andmovable upon the valve-stem, a pair of stops upon said stem for limitingthe'movement of the valve upon the stem, and means for admittingfluid-pressure to the control]ing-cylinder.

11; In a drainage and relief device for cylinders, the combination witha casing, of a valve thereinadapted to open and close a port in saidcasing, a follower having parts projecting through slots in said casing,a spring interposed between said follower and valve, and a nut threadedonto the exterior of the casing and engaging said follower.

12. In a drainage and relief device for cylinders, the combination witha casing, of a valve therein adapted to open and close a port in' saidcasing, a follower having parts projecting through slots in said casing,'a' spring interposed between said follower and valve, and a nutthreaded onto the exterior of the casing, said nut'having notchesadapted to be engaged by theprojecting parts of said follower.

13. In a drainage and relief device, acasing, a normally open valvetherein adapted to close by internal fiuid-pressure,fixed stops forlimiting the opening movement of the valve, and an adjustable stop alsoadapted to limit the movement of the valve, or to close the same. 14. Ina drainage and relief device, a casing,

a normally open valve therein adapted to close by internalfluid-pressure, a normally closed valve adapted to open by excessiveinternal pressure, and an adjustable rod extending through said lattervalve and adapted to limit the movement of the normally open valve orhold the latter closed.

15. In a drainage and relief device for engine-cylinders, a casinghaving a normally open valve therein adapted to close by thefluidpressure from the engine-cylinder, a controlling-cylinder, a pistonwithin said controllingcylinder, a rod operatively connected to saidpiston and adapted to abut against and close said valve when the pistonis moved in one direction, and means for admitting fluid-pressure intosaid controlling-cylinder.

16. In a drainage and relief device for cylinders, a casing having anormally open valve and a normally closed valve, in combination with acontrolling-cylinder, a piston therein, means for admittingfluid-pressure to each end of said cylinder, and means connected withthe piston for holding said normally open valve closed and for holdingsaid normally closed valve open.

17. In a drainage and relief device for cylinders, a casing, a normallyopen valve and a normally closed valve therein, a tubular valvestemconnected to the latter valve, a rod extending through and movablewithin said stem, and a piston adapted to move said rod against andclose the normally open valve.

18. In a drainage and relief device for cylinders, a casing, a normallyopen valve and a normally closed valve therein arranged opposite oneanother, a controlling-cylinder connected to the casing, atubularvalve-stem connected to said normally closed valve and extending intothe controlling-cylinder, a piston in the controlling-cylinder securedto said stem, a rod movable through said stem and having one end withinthe controlling-cylinder and its opposite end arranged to engage thenormally open valve, and a piston within the controlling-cylindersecured to said rod.

19. In a drainage and relief device for cylinders, a casing, a normallyopen valve and a normally closed valve therein arranged opposite oneanother, a controlling-cylinder connected to the casing, a tubularvalve-stem connected to said normally closed valve and extending intothe controlling-cylinder, a piston in the controlling-cylinder securedto said stem, a rod movable through said stem and having one end withinthe controlling-cylinder and its opposite end arranged to engage thenormally open valve, a piston within the controlling-cylinder secured tosaid rod, and a spring interposed between said latter piston and thetubular stem.

20. In a drainage and relief device for engine-cylinders, a casing, anormally open valve therein adapted to close by fluid-pressure from thecylinder, a controlling-piston arranged to hold said valve inoperativein its open position, and means comprising a controllingvalve, formoving said piston-by fluid-pressure.

21. In a drainage and relief device for engine-cylinders, a casing,anormall y open valve therein adapted to close by fluid-pressure fromthe cylinder, a controlling-cylinder, a piston within saidcontrolling-cylinder, and connections between said piston and valve,whereby, when the piston is moved in one direction, the valve will beclosed, and means for admitting fluid-pressure to saidcontrolling-cylinder to move the piston.

22. In a drainage and relief device for engine-cylinders,acasing,aspring-pressed valve normally closing a port in said casing, acontrolling-cylinder and a piston within said cylinder, a rod connectingsaid valve and piston, and means for moving said piston by fluidpressureto open the valve.

23. In a drainage and relief device for engine-cylinders,a casing,anormally open drainage-valve therein adapted to close by the normalinternal fluid-pressure, a normally closed excess-pressure valve adaptedto open by excessive internal fluid-pressure, and means for holding saidlatter valve open comprising a controlling-cylinder, a piston thereinoperatively connected to the excess-pressure valve, and means foradmitting fluid under pressure into said controlling-cylinder.

2 1. In a drainage and relief device for engine-cylinders, a casing,anormally open drainage-valve and a normally closed excess-pressure valvetherein, a controlling-cylinder secured to said casing, a rod extendingthrough said excess-pressure valve and adapted, when moved in onedirection, to abut against and close the normally open valve and whenmoved in the opposite direction to open the excesspressure valve, apiston within the controllingcylinder connected to said rod, a springarranged to hold said rod out of engagement with the normally openvalve.

In testimony whereof I aflix my signaturein presence of two witnesses.

MORRIS R. ZEHNDER. W'itnesses:

C. R. BEDFORD, A. L. DENMAN.

